Smithsonian Report. 1936. — Conger 



Upper, Highly magnified imrtiou ofsheU of Biddulphiafavus (Ehr.) V'.H., showing secondary pore structure. 



X 800. 



Lower left and center, A Surirella, showing dovetailed margin of girdle for attachment to the shell. X 300. 



Loner right, Urammatophora serpentina Ehr., showing internal septal walls. 



